Same here. Also reported an issue on github. Maybe we get an answer.
Which WordPress Version do you use?
Nope not so far, it wasn’t really clear who’s fault it was (I think it was a languageplugin) but I fixed it. How does it work for you now?
Got the same error recently, if I deactivate the plugin it disappears. Some people said you can disable the warnings with an @ before the lines named in your warning but that shouldn’t really the solution.
